This invention relates generally to controlling a speed of a vehicle and, more particularly, to methods and a system for time of arrival control of a vehicle using time of arrival uncertainty.
At least some known aircraft are controlled in three dimensions: latitude, longitude, and altitude. There has been extensive operational experience in three dimensions as evidenced by advances made in Required Navigation Performance (RNP). The computation of the uncertainty associated with navigation performance for flight crews has been developed to enable monitoring of the Actual Navigation Performance (ANP) to ensure compliance with applicable RNP. More recently, the ability to control aircraft in the fourth dimension, time, has been shown to enable advanced airspace management resulting in increased capacity. The use of time-based arrival management facilitates earlier landing time assignments and more efficient use of the runway. This also results in economic benefits if each aircraft can determine its desired landing time using its mast fuel optimum flight profile. In addition to the Required Time-of-Arrival (RTA), an estimated Earliest and Latest Time-of-Arrival is also computed using the maximum and minimum operating speeds, respectively. However, there may be uncertainties and errors associated with the data and methods used to compute these arrival times. There is currently no method to accurately compute, transmit to other systems for further processing, and display the uncertainty associated with any time computation or time control mechanism, given the uncertainties associated with the data used to compute the time of arrival.